Multiwindow operating systems which display multiple programs that are running concurrently as multiple windows are widely used for business and personal use in these days. Typical multiwindow systems include Windows® operating system from Microsoft Corporation, MacOS® from Apple Inc., and X Window System from UNIX®.
In a data processing system having a multiwindow operating system, the efficiency of operation of a window object (hereinafter simply referred to as a “window”) on a display device has a great impact on user productivity. For example, it is important to quickly switching between applications by efficiently changing the order in which windows are stacked. Accordingly, companies in the computer industry have developed the following techniques for improving window operations.
Japanese Published Unexamined Patent Application No. 10-207678 discloses a method for switching between window displays in which some of windows are iconized and the others are displayed in a normal manner on the basis of predetermined settings and the priorities of the windows displayed in a normal manner are changed in order.
Japanese Published Unexamined Patent Application No. 5-241754 discloses a multiwindow display device in which the order in which intricately stacked windows is changed by specifying a window number through a keyboard to select a desired window, rather than displaying a desired window at the top of the stack by clicking to select the window.
Japanese Published Unexamined Patent Application No. 9-330198 discloses a method for displaying windows in which a particular window is always displayed at the bottom of a stack and, when the order in which windows are displayed is changed, detection is made as to whether the particular window is displayed at the bottom and, if not, the particular window is displayed at the bottom of the stack.
Japanese Published Unexamined Patent Application No. 2001-209523 discloses a method for displaying windows in which a certain region is set in an image displayed and the image contained in the set region is always displayed as the top layer.    Patent Document 1: Published Unexamined Patent Application No. 10-207678    Patent Document 2: Published Unexamined Patent Application No. 5-241754    Patent Document 3: Published Unexamined Patent Application No. 9-330198    Patent Document 4: Published Unexamined Patent Application No. 2001-209523
Typically, a user of a multiwindow operating system can bring a particular window that is not on the top of a stack to the top to make it active by clicking the window. The user can mistakenly click a window other than a window to be activated to raise it to the top. In such a case, the user probably wants to restore the stacking order of the windows to the state immediately before the clicking simply by a “single” user action.
However, depending on the number of windows and the state of stacking, the stack order immediately before clicking cannot be restored by a “single” action (for example, a click on the window that was at the top of the stack immediately before the clicking). For example, consider a case where a user mistakenly click window 403 instead of window 404 to raise the window to the top of the stack on a desktop screen (FIG. 4) on which windows 401, 402, 403, and 404 are stacked in this order viewed from the top. As a result of the erroneous operation, the windows are displayed in the following stacking order viewed from the top: windows 403, 401, 402, and 404. When the user clicks window 401, which was at the top of the stack immediately before mistakenly clicking, in order to restore from the erroneous operation, the order in which the windows are stacked changes as follows: windows 401, 403, 402, and 404, viewed from the top. It is difficult to restore by a “single” action the order in which the windows were stacked immediately before the erroneous click, as windows 401, 402, 403, and 404 in this order.
It will be understood from the foregoing that several user actions may be required in order to restore the previous state when a user has erroneously performed a window operation, adversely affecting the user's productivity. The conventional techniques including those disclosed in Patent Documents 1 to 4 and combinations of these cannot solve the problem.
One of the objects of the present invention is to provide a method, program, and data processing system for manipulating display of multiple display objects (preferably window objects) on a display device that are ordered and at least partially overlap one another.